This career development proposal will provide a promising young researcher, Dr. Sean C. Lucan, with the additional knowledge, tools, and skills needed to become an independent investigator. Dr. Lucan's work focuses on adolescent obesity, diet-related diseases, and the food environment. The proposed K award will focus additional training in geographic information systems (GIS), and provide supporting training in 'big-data' management, multilevel statistics, behavioral and social-science theory, and community engagement. Training activities will include coursework and directed study under expert mentors and advisers. Dr. Lucan will apply lessons from training activities to an innovative patient-oriented research project. The project will link patient information to data fro community observation. The proposed training and research will facilitate transition from supervised study to independent investigation, culminating in the submission of an R01 application. Dr. Lucan and his mentors and advisers designed research and training plans to address limitations in the existing scientific literature and in Dr. Lucan's own skill set. Regardig the existing scientific literature, research suggests that neighborhoods around adolescents' homes and schools-most notably in low-income and minority communities-offer and promote chiefly fast foods, processed foods, and other less-healthy convenience items, and that such environments are associated with poorer diets and poorer health among adolescents. However, prior studies have been limited in several important ways: (1) using mostly inaccurate pre-existing datasets on food sources; (2) considering only a limited range of food sources; (3) categorizing food sources only as healthy (like supermarkets) or unhealthy (like fast-food outlets), ignoring huge variations in foods actually sold within each type of food source; (4) considering different types of food sources in isolation rather than in concert; and (5) using convenient but problematic definitions of 'neighborhoods' around homes or schools. Given these limitations, it is not clear how public health might best intervene to change neighborhood 'food environments' to make healthier eating the easier option (or an option at all) and unhealthy eating more difficult (or at least not the only option) for adolescents. The proposed project will be innovative in its use of adolescent research assistants and GIS to explore how a full range of directly-measured food sources simultaneously contribute to food environments within walking distance of adolescents' schools and homes. The research will assess links between food sources, dietary intake, and diet-related health measures for adolescent patients, and capitalize on a unique health system dataset, generated through an electronic medical record (EMR) containing both clinical and survey data. The research will use behavioral and social-science theory to guide data collection and analysis. Analysis will be community-informed and identify targets for intervention, which Dr. Lucan will test in future R01 applications. Regarding Dr. Lucan's own skill set, in order to conduct the type of research that will move the field and his career forward, Dr. Lucan has identified one major areas of focus for coursework and mentored study (GIS mapping and spatial analytics) and three supporting areas (multilevel statistical analyses, 'big data' management, and behavioral and social-science theory along with community engagement). Dr. Lucan will enroll in a formal certificate program in GIS, and take courses in behavioral and social-science theory, multilevel modeling, and secure data handling. These learning activities will find practical applications in the research, with GIS to define and analyze neighborhood food sources, data management to link food-source data to patient information and other data sources, behavioral and social-science theory to inform multilevel statistical modeling, and community engagement to help interpret results. The research and training activities will produce an experienced patient-oriented researcher with the skills to analyze multilevel, diverse, big spatial data. Training will occur under a team of committed, expert mentors and advisers in a superlative research and learning environment. Both institution and department rank highly in NIH funding and there are exceptional resources, facilities, personnel, partnerships, and expertise to support Dr. Lucan's project and training needs. There is experience with multilevel geospatial considerations in patient- oriented research and tremendous expertise in behavioral and social sciences and community engagement involving adolescents. Veteran supervising faculty has wide-ranging current and historical ties to NICHD. The proposed K23 application builds logically on Dr. Lucan's pilot work, both establishing new professional relationships and deepening nascent collaborations. The mentoring and research will expand Dr. Lucan's knowledge and skills, providing the training and practical experience needed to support a career as an independent investigator.